From 1244c6c22acefe5371f788a205bf547ebefb3dd7 Mon Sep 17 00:00:00 2001
From: Artem Bilan <abilan@pivotal.io>
Date: Wed, 15 Nov 2017 15:21:14 -0500
Subject: [PATCH] The log() in the end IMPORTANT note in dsl.adoc

---
 .../dsl/IntegrationFlowDefinition.java        |  3 ---
 src/reference/asciidoc/dsl.adoc               | 22 ++++++++++++++++++-
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/spring-integration-core/src/main/java/org/springframework/integration/dsl/IntegrationFlowDefinition.java b/spring-integration-core/src/main/java/org/springframework/integration/dsl/IntegrationFlowDefinition.java
index 50395b93a3..a0b9c747e1 100644
--- a/spring-integration-core/src/main/java/org/springframework/integration/dsl/IntegrationFlowDefinition.java
+++ b/spring-integration-core/src/main/java/org/springframework/integration/dsl/IntegrationFlowDefinition.java
@@ -2742,9 +2742,6 @@ public abstract class IntegrationFlowDefinition<B extends IntegrationFlowDefinit
 			return target;
 		}
 		Advised advised = (Advised) target;
-		if (advised.getTargetSource() == null) {
-			return null;
-		}
 		try {
 			return extractProxyTarget(advised.getTargetSource().getTarget());
 		}
diff --git a/src/reference/asciidoc/dsl.adoc b/src/reference/asciidoc/dsl.adoc
index 82ec5ae660..516e5744d3 100644
--- a/src/reference/asciidoc/dsl.adoc
+++ b/src/reference/asciidoc/dsl.adoc
@@ -460,7 +460,7 @@ Of course we register some custom `BytesToIntegerConverter` within `ConversionSe
 
 For convenience to log the message journey throw the Spring Integration flow (`<logging-channel-adapter>`), a `log()` operator is presented.
 Underneath it is represented by the `WireTap` `ChannelInterceptor` and `LoggingHandler` as subscriber.
-It is responsible to log message incoming into the next endpoint:
+It is responsible to log message incoming into the next endpoint or for the current channel:
 
 [source,java]
 ----
@@ -491,6 +491,26 @@ public IntegrationFlow loggingFlow() {
 }
 ----
 
+[IMPORTANT]
+=====
+If `log()` or `wireTap()` are used in the end of flow they are considered as one-way `MessageHandler` s.
+If the integration flow is expected to return reply, the `bridge()` should be used in the end, after `log()` or `wireTap()`:
+[source,java]
+----
+@Bean
+public IntegrationFlow sseFlow() {
+    return IntegrationFlows
+        .from(WebFlux.inboundGateway("/sse")
+            .requestMapping(m ->
+                m.produces(MediaType.TEXT_EVENT_STREAM_VALUE)))
+        .handle((p, h) -> Flux.just("foo", "bar", "baz"))
+        .log(LoggingHandler.Level.WARN)
+        .bridge()
+        .get();
+}
+----
+=====
+
 [[java-dsl-flows]]
 === Working With Message Flows